package com.rui.reggie.controller;

import com.rui.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

/**
 * @author : [锐神NO.3]
 * @version : [v1.0]
 * @className : CommonController
 * @createTime : [2022/5/20 14:28]
 * @description : [文件的上传和下载控制器]
 */

@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    /**
     * 从application.yml配置文件中取出文件路径
     */
    @Value("${godrui.path}")
    private String basePath;

    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) {
        log.info(file.toString());

        //原始文件名
        String originalFilename = file.getOriginalFilename();

        //将原始文件名的后缀截取出来
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));

        //使用uuid重新生成文件名，防止文件名重复
        String fileName = UUID.randomUUID().toString() + suffix;

        //创建一个目录对象
        File dir = new File(basePath);

        //如果目录不存在，创建目录
        if(!dir.exists()) {
            dir.mkdirs();
        }

        try {
            //将零时文件file转存到指定位置
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return R.success(fileName);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) {
        try {
            //输入流， 通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));

            //输出流，通过输出流将文件写回浏览器， 在浏览器里展示图片
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int length = 0;
            byte[] bytes = new byte[1024];
            while((length = fileInputStream.read(bytes)) != -1) {
                outputStream.write(bytes, 0, length);
                outputStream.flush();
            }

            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

    }
}
